Zoom dual-aperture camera with folded lens

ABSTRACT

Zoom digital cameras comprising a Wide sub-camera and a folded fixed Tele sub-camera. The folded Tele sub-camera may be auto-focused by moving either its lens or a reflecting element inserted in an optical path between its lens and a respective image sensor. The folded Tele sub-camera is configured to have a low profile to enable its integration within a portable electronic device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation in Part (CIP) of U.S. patentapplication Ser. No. 14/455,906 titled “Zoom dual-aperture camera withfolded lens,” the entire contents being hereby incorporated herein byreference.

FIELD

The presently disclosed subject matter is generally related to the fieldof digital cameras, and in particular to multiple-aperture digitalcameras.

BACKGROUND

In recent years, mobile devices such as cell-phones (and in particularSmartphones), tablets and laptops have become ubiquitous. Such devicescommonly include one or two compact digital cameras e.g. a mainrear-facing camera (i.e. a camera on the back side of the device, facingaway from the user and often used for casual photography) and asecondary front-facing camera (i.e. a camera located on the front sideof the device and often used for video conferencing).

The design of many of these cameras is similar to the traditionalstructure of a digital still camera, i.e. they comprise an opticalcomponent (or a train of several optical elements and a main aperture)placed on top of an image sensor (also referred to henceforth simply as“sensor”). The optical component (also referred to as “optics”) refractsthe incoming light rays and bends them to create an image of a scene onthe sensor.

The dimensions of these cameras are largely determined by the size ofthe sensor and by the height of the optics. These are usually tiedtogether through the focal length (f) of the lens and its field of view(FOV)—a lens that has to image a certain FOV on a sensor of a certainsize has a specific focal length. Keeping the FOV constant, the largerthe sensor dimensions (e.g. in an X-Y plane), the larger the focallength and the optics height.

As the dimensions of mobile devices (and in particular the thickness ofdevices such as Smartphones) are constantly being diminished, compactcamera dimensions are becoming an increasingly limiting factor on devicethickness. Several approaches have been proposed to reduce compactcamera thickness in order to alleviate this constraint. Recently,multi-aperture systems have been proposed for this purpose. In suchsystems, instead of having one aperture with one train of opticalelements, the camera is divided into several apertures, each withdedicated optical elements, and all sharing a similar field of view.Hereinafter, each such aperture, together with the optics and the sensorarea on which the image is formed, is defined as a “sub-camera”. Imagesfrom the sub-cameras are fused together to create a single output image.

In some multi-aperture camera designs, each sub-camera creates a smallerimage on the image sensor compared with the image created by a referencesingle-aperture camera. Therefore, the height of each sub-camera can besmaller than the height of a single-aperture camera, reducing the totalheight of the camera and allowing for slimmer designs of mobile devices.

Dual-aperture zoom cameras in which one sub-camera has a wide FOV (“Widesub-camera”) and the other has a narrow FOV (“Tele sub-camera”) areknown. One problem with dual-aperture zoom cameras relates to the heightof the zoom Tele sub-camera. There is a significant difference in theheight (also known as “total track length” or “TTL”) of Tele (“T”) andWide (“W”) sub-cameras. The TTL is typically defined as the maximaldistance between the object-side surface of a first lens element and acamera image sensor plane. In most miniature lenses, the TTL is largerthan the lens effective focal length (EFL). A typical TTL/EFL ratio fora given lens (or lens unit) is around 1.3. In a single-apertureSmartphone camera with a ⅓-¼″ sensor, EFL is typically between 3.5 and4.5 mm, respectively, leading to a FOV of 70-80°.

Assuming, for example, one wishes to achieve a dual-aperture ×2 opticalzoom in a Smartphone, it would be natural to use EFL_(W)=3.5 mm andEFL_(T)=2×EFL_(W)=7 mm. However, without spatial restrictions, the Widelens will have an EFL_(W)=3.5 mm and a TTL_(W) of 3.5×1.3=4.55 mm, whilethe Tele lens will have EFL_(T)=7 mm and TTL_(T) of 7×1.3=9.1 mm. Theincorporation of a 9.1 mm lens in a Smartphone camera would lead to acamera height of around 10 mm, which is unacceptable for many Smartphonemanufacturers.

An example of a solution to the aforementioned problem is described inco-invented and co-owned PCT patent application PCT/IB2014/062180 titled“Dual-aperture zoom digital camera”. Some of the principles of thissolution are shown in FIG. 1 schematically illustrating an embodiment ofa dual-aperture zoom camera with auto-focus (AF) and numbered 100, in(a) a general isometric view, and (b) a sectioned isometric view.

Camera 100 comprises two sub-cameras, labeled 102 and 104, eachsub-camera having its own optics. Thus, sub-camera 102 includes anoptics bloc 106 with an aperture 108 and an optical lens module 110, aswell as a sensor 112. Similarly, sub-camera 104 includes an optics bloc114 with an aperture 116 and an optical lens module 118, as well as asensor 120. Each optical lens module may include several lens elementsas well as an Infra-Red (IR) filter 122 a and 122 b. Optionally, some orall of the lens elements belonging to different apertures may be formedon the same substrate. The two sub-cameras are positioned next to eachother, with a small baseline in the 124 between the center of the twoapertures 108 and 116. Each sub-camera can further include an AFmechanism, respectively 126 and 128, controlled by a controller (notshown). Camera 100 is “thin” as expressed by TTL/EFL for eachsub-camera. Typically, TTL_(W)/EFL_(W)>1.1 and TTL_(T)/EFL_(T)<1.0 (e.g.0.85).

While the zoom range in camera 100 is about ×2, it would be advantageousto further increase this range. However, this requires increasingfurther the Tele lens EFL (EFL_(T)), which will cause an increase in thecamera height. An increase of EFL_(T) to exemplarily 12 mm will resultin an undesirable camera height of for example 0.85×12+0.9=11.1 mm.

GENERAL DESCRIPTION

As noted above, the requirements for digital cameras for use in portableelectronic devices are related to the dimensions and image quality ofthe camera. Moreover, these requirements become more essential when thecamera is to be installed within the portable device, unlike otherexternal camera units attachable to the portable device.

In the case of an internal (integral) camera unit, a camera is requiredto have dimensions as small as possible in order to fit the thickness ofthe device in which the camera is installed (preferably withoutprotruding from the device's casing), while being suitable to operatewith commonly used image sensors. This problem is even more crucial whenusing a Tele lens with a long effective focal length (EFL) to obtain arelatively high zooming effect.

Thus, according to one aspect of the presently disclosed subject matter,there is provided a zoom digital camera comprising a Wide sub-camera anda Tele sub-camera. The Wide sub-camera comprises a Wide lens module anda Wide image sensor, the Wide lens module having a Wide lens symmetryaxis along a first optical path between an object side and the Wideimage sensor. The Wide sub-camera is configured to provide a Wide image.

The Tele sub-camera comprises a Tele lens module and a Tele image sensorand a first reflecting element. The Tele lens module has a Tele lenssymmetry axis along a second optical path, the Tele lens symmetry axispositioned substantially perpendicular to the Wide lens symmetry axis.The Tele sub-camera is configured to provide a Tele image.

The first reflecting element has a first reflecting element symmetryaxis inclined substantially at 45 degrees to both the Wide lens symmetryaxis and the Tele lens symmetry axis and is operative to provide afolded optical path between the object and the Tele image sensor.Accordingly, the Tele sub-camera is considered to be folded and isreferred to herein as “folded Tele sub-camera”.

The Wide lens has a Wide field of view (FOV_(W)) and the Tele lens has aTele field of view (FOV_(T)) narrower than FOV_(W). According to onenon-limiting example, the Tele sub-camera provides an X5 zooming effect,compared to the Wide sub-camera.

The digital camera is operatively connected to at least one imageprocessor configured to process the Tele image and the Wide image intoan output image. Methods of fusing images received through differentoptical paths into a single output image are provided for example inco-invented and co-owned PCT patent application, publication no.WO2014/083489 titled “HIGH-RESOLUTION THIN MULTI-APERTURE IMAGINGSYSTEMS”, and co-invented and co-owned U.S. patent application Ser. No.14/365,711 titled “DUAL APERTURE ZOOM DIGITAL CAMERA” which areincorporated herein by reference and discloses a multi-aperture imagingsystem comprising a first camera with a first sensor that captures afirst image, and a second camera with a second sensor that captures asecond image. Either image may be chosen to be a primary or an auxiliaryimage, based on a zoom factor. An output image with a point of viewdetermined by the primary image is obtained by registering the auxiliaryimage to the primary image.

In order to further adapt the dimensions of the folded Tele sub-camerato the trend in electronic portable devices, seeking to reduce theirthickness as much as possible, various features of the folded Telesub-camera were specifically configured to enable to achieve a foldedTele sub-camera with reduced height. Reduction of the Tele-sub cameraheight enables to reduce the overall height of a dual aperture camera.Furthermore, reduction of the folded Tele sub-camera height was achievedwhile maintaining a desirable image quality.

Thus, in addition to the above features, according to various examplesof the presently disclosed subject matter, the zoom digital camera cancomprise one or more of features (1) to (32) below, in any desiredcombination and permutation.

1) wherein the Tele lens module of the folded Tele sub-camera comprisesa group of at least 3 lens elements and wherein the lens elements in thegroup are designed to have a diameter substantially not exceeding thediameter of an aperture of the Tele sub-camera. As explained below, thisis different than conventional lens modules where the diameters of thelenses are designed to be increasingly wider towards the sensor.

2) wherein the Tele lens module of the folded Tele sub-camera comprisesa group of 3 to 5 lens elements.

3) wherein the Tele sub-camera further comprises a substrate, astructure for holding the lens elements in place, and a camera casing.

4) wherein the aperture of the Tele sub-camera is designed to provide asufficiently low F# (e.g. equal or smaller than 3) to increase lightfalling on the Tele image sensor.

5) wherein the Tele lens module is designed to enable to generate animage on an entire area of the Tele image sensor. The Tele image sensorcan be for example a ⅓″ image sensor or a ¼″ image sensor.

6) wherein the lens elements in the group are designed such that blockedlight does not exceed a certain percentage of the light entering theTele lens module (e.g. not more than 25% of light entering the Tele lensmodule is blocked).

7) wherein according to one example the Tele sub-camera is configured tohave the following technical parameters: an EFL>9 mm, an F#≦3 and lightblockage does not exceed more than 25% of light entering the Telesub-camera aperture for all viewing angles.

8) wherein the Tele sub-camera is characterized by a height notexceeding 6.5 mm.

9) wherein the Tele sub-camera is characterized by a height notexceeding 5.7 mm.

10) wherein the Tele image sensor lies in a plane substantiallyperpendicular to the Tele lens symmetry axis.

11) wherein the Tele sub-camera comprises a Tele auto-focus (AF)mechanism configured to move the Tele lens along the Tele symmetry axis;the AF mechanism is designed such that its height substantially does notexceed the height of a Tele lens module.

12) wherein the AF mechanism comprises one or more magnets coupled torespective coils, positioned laterally on one or two sides of the Telelens module, the magnets having a height substantially not exceeding theheight of the Tele lens module.

13) wherein the AF mechanism comprises only one magnet coupled to arespective coil.

14) wherein the camera further comprises a second reflecting elementpositioned in the second optical path between the Tele lens module andthe Tele image sensor, the second reflecting element being configured todirect light that propagates parallel to the second optical path to thefirst optical path, wherein the Tele image sensor lies in a planesubstantially perpendicular to the Wide lens symmetry axis.

15) wherein the camera further comprises a Tele auto-focus (AF)mechanism configured to move the second reflecting element along asecond reflecting element symmetry axis.

16) wherein the Wide and Tele image sensors are mounted on a singleprinted circuit board.

17) wherein at least one processor operatively connected to the camerais configured to use a zoom factor (ZF) to determine a respective outputfield of view.

18) wherein the Wide lens module has a Wide field of view FOV_(W) andthe Tele lens module has a Tele field of view FOV_(T) narrower thanFOV_(W); the camera further comprises a Mid sub-camera that includes aMid lens module with a field of view FOV_(M) that fulfillsFOV_(W)>FOV_(M)>FOV_(T) and a Mid image sensor, the Mid lens having aMid lens symmetry axis; the Mid camera is configured to provide a Midimage.

19) wherein the Mid sub-camera is configured with an EFL which equals toa geometric average of an EFL of the Wide sub-camera and an EFL of theTele sub-camera.

20) wherein at least one processor operatively connected to the camerais configured to process the Mid image together with the Tele image orthe Wide image into an output image.

21) wherein the Mid lens symmetry axis is substantially perpendicular tothe Wide lens symmetry axis and the Mid image sensor lies in a planesubstantially perpendicular to the Mid lens symmetry axis; and whereinthe Tele image sensor lies in a plane substantially perpendicular to theTele lens symmetry axis.

22) wherein the camera further comprises a Mid auto-focus (AF) mechanismconfigured to move the Mid lens module along the Mid symmetry axis,which is substantially perpendicular to the Wide lens symmetry axis; anda Tele AF mechanism configured to move the Tele lens module along theTele symmetry axis; either of the Mid AF mechanism and Tele AF mechanismhave a height substantially not exceeding the height of the Tele lensmodule.

23) wherein the Mid AF mechanism comprises one or more magnets coupledto respective coils, positioned laterally on one or two sides of theTele lens module, the magnets having a height substantially notexceeding the height of the Tele lens module.

24) wherein the Mid AF mechanism comprises only one magnet coupled to arespective coil.

25) wherein the camera further comprises a third reflecting elementinclined substantially at 45 degrees to both the Wide lens symmetry axisand the Mid lens symmetry axis; the third reflecting element isconfigured to provide a folded optical path between the object side andthe Mid image sensor.

26) wherein the camera further comprises a fourth reflecting elementpositioned in a fourth optical path between the Mid lens and the Midimage sensor, the fourth reflecting element configured to direct lightthat propagates parallel to the second optical path to the first opticalpath, wherein the Mid image sensor lies in a plane substantiallyparallel to the Mid lens symmetry axis.

27) wherein the camera further comprises a Mid auto-focus (AF) mechanismconfigured to move the fourth reflecting element along a fourthreflecting element symmetry axis.

28) wherein a Mid lens symmetry axis of the Mid sub-camera issubstantially parallel to the Wide lens symmetry axis and the Wide andMid image sensors are mounted on a single printed circuit board.

29) wherein a Mid lens symmetry axis of the Mid sub-camera issubstantially perpendicular to the Wide lens symmetry axis and the Wideand Mid image sensors are mounted on a single printed circuit board.

30) wherein at least one processor operatively connected to the camerais configured to use a zoom factor (ZF) to determine a respective outputfield of view.

31) wherein at least one processor operatively connected to the camerais configured to output an output image formed by using Wide and Midimages for a ZF that sets a FOV between FOV_(W) and FOV_(M).

32) wherein at least one processor operatively connected to the camerais configured to output an output image formed by using Mid and Teleimages for a ZF that sets a FOV between FOV_(M) and FOV_(T).

According to one example, the presently disclosed subject matterincludes a digital camera configured to be integrated within a casing ofan electronic device, the camera comprising: a Wide sub-camera, a Telesub-camera and a Tele auto-focus (AF) mechanism;

the Wide sub-camera comprising, a Wide lens module and a Wide imagesensor, the Wide lens module having a Wide lens symmetry axis along afirst optical path between an object side and the Wide image sensor; theWide sub-camera configured to provide a Wide image; a Tele sub-cameracomprising, a Tele lens module and a Tele image sensor and a firstmirror; the Tele lens module having a Tele lens symmetry axis along asecond optical path, the Tele lens symmetry axis positionedsubstantially perpendicular to the Wide lens symmetry axis; the Telecamera is configured to provide a Tele image; the first mirror has afirst mirror symmetry axis inclined substantially at 45 degrees to boththe Wide lens symmetry axis and the Tele lens symmetry axis and isoperative to provide a folded optical path between the object and theTele image sensor;

wherein the Tele lens module comprises a group of 3 to 5 lens elementsand wherein the lens elements in the group are designed to have adiameter substantially not exceeding the diameter of an aperture of theTele sub-camera, to enable the generation of an image on an entire areaof the Tele image sensor, and to enable passage of at least 75% of lightentering the Tele lens module, towards the Tele image sensor;

wherein the Tele AF mechanism is configured to move the Tele lens alongthe Tele symmetry axis; the AF mechanism comprises one or more magnetscoupled to respective coils, positioned laterally on one or two sides ofto the Tele lens module, the magnets having a height substantially notexceeding the height of the Tele lens module.

The presently disclosed subject matter further contemplates a mobileelectronic device such as a cell phone (e.g. Smartphone), portablecomputer, notepad, tablet, watch, any type of electronic wearable device(e.g. bracelet, watch, helmet, glasses, etc.), or the like, which isequipped with a digital camera as disclosed herein. According to someexamples, the digital camera is fully integrated within the electronicdevice (i.e. without protruding from the casing of the electronicdevice).

The presently disclosed subject matter further contemplates a FoldedTele sub-camera having a low camera profile as disclosed above.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting examples of embodiments disclosed herein are describedbelow with reference to figures attached hereto that are listedfollowing this paragraph. The drawings and descriptions are meant toilluminate and clarify embodiments disclosed herein, and should not beconsidered limiting in any way. Like elements in different drawings maybe indicated by the same numerals.

FIG. 1 shows schematically the design of a dual-aperture camera withzoom and AF;

FIG. 2A shows schematically a zoom and auto-focus dual-aperture camerawith folded Tele lens module in (a) a general isometric view, and (b) aside view, according to an example of the presently disclosed subjectmatter;

FIG. 2B shows schematically in a general isometric view a zoom andauto-focus dual-aperture camera with folded Tele lens module, accordingto an example of the presently disclosed subject matter;

FIG. 3 shows schematically a zoom and auto-focus dual-aperture camerawith folded Tele lens module disclosed herein in (a) a general isometricview, and (b) a side view, according to an example of the presentlydisclosed subject matter;

FIG. 4 shows schematically a zoom and auto-focus dual-aperture camerawith folded Tele lens module disclosed herein in (a) a general isometricview, and (b) a side view, according to an example of the presentlydisclosed subject matter;

FIG. 5 shows schematically details of the auto-focus mechanism formoving the second mirror in the example shown in FIG. 4 in (a) a generalisometric view, and (b) a cross sectional view through section A-A;

FIG. 6A shows schematically in a general isometric view a zoom andauto-focus triple-aperture camera with one folded Tele lens according toan example of the presently disclosed subject matter;

FIG. 6B shows schematically in a general isometric view a zoom andauto-focus triple-aperture camera with one folded Tele lens, accordingto an example of the presently disclosed subject matter;

FIG. 6C shows schematically in a general isometric view a zoom andauto-focus triple-aperture camera with one folded Tele lens according toan example of the presently disclosed subject matter;

FIG. 7 shows schematically in a general isometric view a zoom andauto-focus triple-aperture camera with two folded lenses, according toan example of the presently disclosed subject matter;

FIG. 8 shows schematically in a general isometric view a zoom andauto-focus triple-aperture camera with two folded Tele lenses, accordingto an example of the presently disclosed subject matter;

FIG. 9 shows graphs illustrating in: (a) user experience of resolutiongain vs. zoom factor in an ideal continuous zoom; (b) user experience ofresolution gain vs. zoom factor with a camera that includes two, Wideand Tele sub-cameras with 13 Mega pixel sensors and a 2 Mega pixelviewer; and (c) user experience of resolution gain vs. zoom factor witha camera that includes three, Wide, Mid and Tele sub-cameras with 13Mega pixel sensors and a 2 Mega pixel viewer, according to an example ofthe presently disclosed subject matter;

FIG. 10A shows a Tele lens module with a five-element Tele lens unitthat can be used in a camera, according to an example of the presentlydisclosed subject matter;

FIG. 10B shows an embodiment of a Tele lens module with a four-elementTele lens unit that can be used in a camera disclosed herein, accordingto an example of the presently disclosed subject matter;

FIG. 10C shows a Tele lens module with a three-element Tele lens unitthat can be used in a camera, according to an example of the presentlydisclosed subject matter;

FIG. 11A illustrates the term “lens optical height” H/2 for each lenselement of a four-element lens unit, according to an example of thepresently disclosed subject matter;

FIG. 11B illustrates the effect of blocked light according to an exampleof the presently disclosed subject matter;

FIG. 12 shows schematically in (a) an isometric view and in (b) anexternal view of a camera module, according to an example of thepresently disclosed subject matter;

FIG. 13 shows schematically in (a) an isometric view and in (b) anexternal view of another camera module, according to an example of thepresently disclosed subject matter; and

FIG. 14 shows schematically a portable electronic device with anintegrated dual-aperture camera with folded Tele lens module, accordingto an example of the presently disclosed subject matter.

DETAILED DESCRIPTION

It is to be understood that when specific direction and/or angle valuesare given herein, they are meant to include a range of values acceptablewithin practical tolerances known in the pertinent field.

Furthermore, for the sake of clarity the term “substantially” is usedherein to imply the possibility of variations in values within anacceptable range. According to one example, the term “substantially”used herein should be interpreted to imply possible variation of up to10% over or under any specified value. According to another example, theterm “substantially” used herein should be interpreted to imply possiblevariation of up to 5% over or under any specified value. According to afurther example, the term “substantially” used herein should beinterpreted to imply possible variation of up to 2.5% over or under anyspecified value. The specified value can be absolute value (e.g.substantially not exceeding 45°, substantially perpendicular, etc.) orrelative (e.g. substantially not exceeding the height of x, etc.).

It is noted, that in the current discussion “aperture diameter” refersto diameter of an aperture in a camera with a constant aperture size orto the maximal aperture diameter in a camera with a variable aperturesize.

As used herein, the phrase “for example,” “such as”, “for instance”, “inan embodiment” and variants thereof describe non-limiting examples ofthe presently disclosed subject matter. It is appreciated that certainfeatures of the presently disclosed subject matter, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the presently disclosed subject matter, which are, forbrevity, described in the context of a single embodiment, may also beprovided separately or in any suitable sub-combination.

It is noted that the term “optic bloc” as used herein refers to the lensmodule together with the auto focus mechanism.

Turning now to FIG. 2A, it shows schematically an embodiment of a zoomand auto-focus dual-aperture camera 200 with folded Tele lens disclosedherein in (a) a general isometric view and (b) a sectioned isometricview. The isometric view is shown related to a XYZ coordinate system.Camera 200 comprises two sub-cameras, a regular Wide sub-camera 202 anda Tele sub-camera 204.

Wide camera 202 includes a Wide optics bloc with a respective aperture208 (indicating object side of the camera) and an optical lens module210 (or “lens module” in short) with a symmetry (and optical) axis 212in the Y direction, as well as a Wide image sensor 214. Tele camera 204includes a Tele optics bloc with a respective aperture 218 and anoptical lens module 220 with a Tele lens symmetry (and optical) axis 222a, as well as a Tele image sensor 224.

Camera 200 further comprises a first flat reflecting element (e.g.mirror or prism) 226 inserted in a “Tele” optical path. The Tele opticalpath is extended from an object (not shown) through the Tele lens module(or simply “Tele lens”) to the Tele sensor and marked by arrows 222 band 222 a. Arrow 222 b indicates the direction from the object side ofthe camera and is substantially parallel to symmetry axis 212 of theWide sub-camera. For simplicity, hereinafter the reflective element isreferred to as “mirror”, however, this is by way of example only andshould not be construed as limiting in any way.

According to one example, the Wide image sensor 214 lies in the X-Zplane, while the Tele image sensor lies a X-Y plane substantiallyperpendicular to the Tele lens symmetry axis 222 a. Various cameraelements may be mounted on a substrate 232, e.g. a printed circuit board(PCB). It may be said that the Tele sensor is “upright” as it lies in aplane substantially perpendicular to that of Wide sensor 214 andsubstrate 232.

Notably, using a Tele sub-camera with a Tele sensor in an uprightposition helps to reduce the length of the Tele sub camera and thereforereduces the overall camera footprint, as compared to a Tele sensorpositioned in the X-Z plane, as described below with reference to FIG.3.

According to one example, mirror 226 is inclined at substantially 45° tothe Tele lens symmetry axis (222 a) and to arrow 222 b. The Tele opticalpath is thus “folded”. Hereinafter, a Tele lens having a folded opticalpath passing therethrough is referred to as a “folded Tele lens” and aTele sub-camera with such a folded lens is referred to as a “folded Telesub-camera”.

Both Wide and Tele sub-cameras may be fixed focus (FF) or auto focus(AF). When present, an AF mechanism for the Wide camera is indicatedgenerally by numeral 206, and in one example it can be similar to themechanism shown in FIG. 1. A new, low profile AF mechanism is describedbelow with reference to FIG. 12 and FIG. 13.

If an AF mechanism is included in the Tele sub-camera, it is appliedsuch that the auto-focus movement is along the Z axis. An AF mechanismmay be coupled to and may be operative to move the Tele lens along the Zaxis in a direction shown by an arrow 230, i.e. parallel to its symmetryaxis 222 a. The Tele lens movement range may be for example between100-500 μm. Camera 200 can further include (or be otherwise operativelyconnected to) a processing unit comprising one or more suitablyconfigured processors (not shown) for processing the Tele image and theWide image into an output image.

The processing unit may include hardware (HW) and software (SW)specifically dedicated for operating with the digital camera.Alternatively, a processor of an electronic device (e.g. its native CPU)in which the camera is installed can be adapted for executing variousprocessing operations related to the digital camera (including, but notlimited to, processing the Tele image and the Wide image into an outputimage).

Camera 200 (as well as other cameras mentioned below) may have,according to some non-limiting examples, dimensions and/or parameters asshown in Table 1. These dimensions (given in millimeters) and-parametersinclude a camera width W, a camera length L, a camera height H, a Widesub-camera effective focal length EFL_(W), a Wide F-number F#_(W), aTele sub-camera effective focal length EFL_(T) and a Tele F-numberF#_(T).

TABLE 1 FIG. W L H EFL_(W) EFL_(M) EFL_(T) F#_(W) F#_(M) F#_(T) 2A  5-1220-50 4-8 2-8 5-25 2-3 2-5 2B 10-25 10-40 4-8 2-8 5-25 2-3 2-5 3  5-1220-50 4-8 2-8 5-25 2-3 2-5 4  5-12 20-50 4-8 2-8 5-25 2-3 2-5 6A  5-1225-60 4-8 2-5 4-10 8-30 2-3 2-3 2-5 6B  5-12 20-50 4-8 2-5 4-10 8-30 2-32-3 2-5 6C 10-25 10-40 4-8 2-5 4-10 8-30 2-3 2-3 2-5 7  5-12 25-60 4-82-5 4-10 8-30 2-3 2-3 2-5 8 10-25 20-50 4-8 2-8 4-20 8-30 2-3 2-5 2-5

For example, the folding of the Tele lens module in camera 200 (as wellas in cameras 300-600 below) enables the use of a Tele lens module withan EFL_(T) of 12 mm while maintaining the overall camera heightsignificantly lower than the height of a camera utilizing a normalupright Tele lens with the same EFL_(T) (e.g. 11.1 mm mentioned in thebackground section above).

In order to provide more clarity and avoid clutter in the followingdrawings, some elements similar to or identical to elements in camera200 may be mentioned, but shown without reference numerals.

FIG. 2B shows schematically, in a general isometric view, anotherembodiment of a zoom and auto-focus dual-aperture camera (200′) withfolded Tele lens module disclosed herein. Camera 200′ includesessentially the same elements as camera 200, and such elements (whennumbered) are numbered accordingly with the same numerals. The twocameras differ mainly in the relative positioning (e.g. on substrate232′) of the Tele and Wide sub-cameras and mirror 226.

As shown, these elements are arranged such that camera 200′ has a“squarer” footprint than camera 200. In particular, a width W in camera200′ is larger than width W in camera 200, while a length L in camera200′ is smaller than L in camera 200. Note that the configuration shown,in which the Wide sub-camera's sides are parallel to respectively the Xand Z axes while the Tele lens is essentially aligned along the Z axis,is shown by way of example only, and that in other embodiments eachsub-camera may be positioned differently. For example, the Widesub-camera may have sides not parallel to the X, Y axes and the Telelens may be aligned in a different direction than Z, as long as theoptical axis, before the folding, is parallel to the Wide camerasymmetry axis. Camera 200′ may have exemplary dimensions and/orparameters shown in Table 1.

FIG. 3 shows schematically yet another embodiment of a zoom andauto-focus dual-aperture camera with folded Tele lens disclosed hereinand numbered 300 in (a) a general isometric view and (b) a sectionedisometric view. Camera 300 is substantially identical to camera 200,except that camera 300 includes a second mirror 302 inserted in theoptical path between the Tele lens and Tele sensor 224, the path markedhere by arrows 304 a and 304 b. In addition, and unlike in cameras 200and 200′ (but as in camera 100), Tele sensor 224 lies in the X-Z plane(same as the Wide sensor). According to one example, the Wide and Telesensors may be placed on the same substrate, e.g. a PCB. Alternatively,each sensor may be mounted on a separate PCB. Both mirrors can beinclined at substantially 45° to the Tele lens symmetry axis 222 a.

As in camera 200, both Wide and Tele sub-cameras may be fixed focus (FF)or auto focus (AF). As in camera 200, an AF mechanism (not shown) iscoupled to and operative to move the Tele lens along the Z axis in adirection shown by an arrow 230, i.e. parallel to symmetry axis 222 a.Camera 300 may have for example, the same dimensions and/or parametersas camera 200 or be larger (e.g. by about 5-10 mm) along the Z axis.

Camera 300 requires that the Tele lens module is designed such that itsback focal length (BFL), i.e. the distance along the optical path fromthe left hand side of the Tele lens barrel to the mirror, and from thereto the Tele image sensor (the combined lengths of arrow 304 a and 304b), is large enough to enable the inclusion of the second mirror. Inaddition, the folded Tele geometry in camera 300 allows direct mountingof the Wide and Tele image sensors on a single common PCB.Alternatively, each sensor may be mounted on a separate PCB. Camera 300can have for example dimensions and/or parameters shown in Table 1.

FIG. 4 shows, schematically, an embodiment of a zoom and auto-focusdual-aperture camera with folded Tele lens disclosed herein and numbered400 in (a) a general isometric view and (b) a sectioned isometric view.Camera 400 is substantially identical to camera 300, except that theTele sub-camera is auto-focused by means of moving the second mirrorusing an AF mechanism (see FIG. 5) 402 coupled thereto. Mechanism 402moves second mirror 302 in a direction perpendicular to its flat plane(e.g. at 45° to the X-Y and X-Z planes) shown by an arrow 430. Themirror movement range may for example, between 100-500 μm.Alternatively, the second mirror 302 can be moved in other directions tofocus the Tele image that is captured by the Tele sensor, for example,along the Z axis or the Y axis. Camera 400 may have for example,dimensions and/or parameters shown in Table 1.

FIG. 5 shows, schematically, details of mechanism 402 in (a) a generalisometric view, and (b) a cross sectional view through section A-A.Mechanism 402 includes an electromagnetic actuator comprising astationary member 404 and a moving member 406. Stationary member 404includes four permanent magnets 408 a-d. Moving member 406, shown heregenerally to have a cylindrical shape with a symmetry axis 410 includesa core 412 surrounded at least partially by a coil 414. Moving member406 is mechanically coupled at one end 416 to mirror 302 and at anopposite end 418 to four springs 420 a-d, which in turn are rigidlycoupled to a stationary frame 422. The number of springs shown isprovided by way of example only, and fewer (e.g. one) or more than foursprings can be used. In use, a current passing through coil 414 leads toa magnetic force that causes moving member 406 and mirror 302 to movealong symmetry axis 410 as indicated by arrow 430.

FIG. 6A shows schematically, in a general isometric view, an embodimentof a zoom and auto-focus triple-aperture camera with one folded Telelens 600 disclosed herein. Camera 600 includes for example, elements andfunctionalities of camera 200. That is, camera 600 includes a Widesub-camera 202 with a Wide lens 210 and a Wide sensor 214, a Telesub-camera 204 with a folded Tele lens 220, a mirror 226 and an“upright” Tele sensor 224.

In this example, the three sub-cameras are substantially aligned in theZ direction along a common axis. As in camera 200, Tele lens auto-focusis achieved by moving the Tele lens along the Z axis in a directionshown by arrow 230. However, in addition to the elements of camera 200,camera 600 further includes a second Tele (referred to as “Mid” or “M”)sub-camera 602 with a Mid lens 604 and a Mid sensor 606. Mid sub-camera602 has an EFL_(M) and a FOV_(M) intermediate to those of the Wide andTele sub-cameras, (see examples in Table 1). A symmetry (and optical)axis 612 of the Mid sub-camera is substantially parallel to axis 212 ofWide sub-camera 202 and direction 222 b in Tele sub-camera 204. Notethat while the Wide and Mid sub-cameras are shown in a particulararrangement (with Mid sub-camera 602 closer to Tele sub-camera 204),this order may be changed such that the Wide and Mid sub-camerasexchange places. Camera 600 may have for example, dimensions and/orparameters shown in Table 1.

In use, an output FOV of camera 600 (as well as camera 600′, 600″, 700and 800) is defined by a zoom factor ZF. Such an FOV may be marked“FOV_(ZF). For example, in zoom-in up to a ZF=ZF_(M) the camera outputis the same as the output of a dual-aperture zoom camera with only Wideand Mid sub-cameras, where the Mid sub-camera replaces the Telesub-camera. When zooming in from ZF_(M) to ZF_(T) the camera output isthe same as the output of a dual-aperture zoom camera with only Mid andTele sub-cameras, where the Mid sub-camera replaces the Wide sub-camera.This provides a “continuous zoom” (i.e. resolution gain vs. ZF)experience. A more detailed explanation of the term “continuous zoom” asused herein, and an example of a continuous zoom experience obtainedwith a camera disclosed herein, are provided with respect to FIG. 8.

FIG. 6B shows schematically, in a general isometric view, anotherembodiment of a zoom and auto-focus triple-aperture camera with onefolded Tele lens disclosed herein and numbered 600′. Camera 600′includes essentially the same elements as camera 600, but the Wide andMid sub-cameras are aligned along the Z direction, while the Telesub-camera has the Z direction as its symmetry axis. As in camera 600,the positions of the Wide and Mid sub-cameras are interchangeable.Camera 600′ may have for example dimensions and/or parameters shown inTable 1.

FIG. 6C shows schematically, in a general isometric view, yet anotherembodiment of a zoom and auto-focus triple-aperture camera with onefolded Tele lens disclosed herein and numbered 600″. Camera 600″includes essentially the same elements as cameras 600 and 600′, but thepositioning of the three sub-cameras is changed such that the foldedTele lens is adjacent to and parallel to a side 608 of Wide sub-camera202 and a side 610 of Mid sub-camera 602. As in cameras 600 and 600′,the positions of the Wide and Mid sub-cameras are interchangeable.Camera 600″ may have, for example, dimensions and/or parameters shown inTable 1.

Note that while the triple-aperture camera with one folded Tele lensembodiments of FIGS. 6A-C are shown as including an “upright” Telesensor 224, other triple-aperture cameras with one folded Tele lensembodiments may include a second mirror and a Tele sensor positioned inthe X-Z plane as in camera 300. One such embodiment is shown in FIG. 7.FIG. 7 shows schematically, in a general isometric view, yet anotherembodiment of a zoom and auto-focus triple-aperture camera with onefolded Tele lens disclosed herein and numbered 700. Camera 700 may beseen essentially as a camera in which a Mid sub-camera 602 is added tothe elements of camera 300. Alternatively, it can be seen as a camera inwhich a second mirror 302 is inserted in the optical path between foldedTele lens 220 and Tele sensor 224. Tele auto-focus may be achieved by(as shown by arrow 430) moving second mirror 302 (as in camera 400), or,alternatively, by moving the Tele lens (as in camera 300). Camera 700may have for example, dimensions and/or parameters shown in Table 1.

FIG. 8 shows schematically, in a general isometric view, an embodimentof a zoom and auto-focus triple-aperture camera with two folded lensesdisclosed herein and numbered 800. Camera 800 may be seen as combiningelements existing in camera 200 with an added “folded” Mid sub-camera802. Thus, as in camera 200, camera 800 may include a Wide sub-camera202 with a Wide lens and Wide sensor, a Tele sub-camera 204 with afolded Tele lens, an upright Tele sensor 224, and a mirror 226. FoldedMid sub-camera 802 includes a Mid lens 804 and an upright Mid sensor806. An added mirror 808 reflects radiation arriving from the objectside in a direction 810 which is parallel to direction 222 b and axis212, through Mid lens 804 to the Mid sensor along a Mid lens symmetryaxis 812, thus providing Mid image data which may be combined with Wideand Tele sub-cameras image data. In some examples, mid lens 804 may bemoved by an AF mechanism (not shown) along its axis 812 in the Zdirection (the movement illustrated by an arrow 830) to provide Midautofocus, similar to the Tele autofocus movement illustrated above byarrow 230.

Alternative embodiments (not shown) of a camera with folded Mid and Telelenses may include additional mirrors and “flat” Mid and Tele sensors(similar to embodiments shown in FIGS. 3, 4 and 7 for the Tele lens).Furthermore, according to this example, autofocus may be achieved bymoving these mirrors instead of the lenses. Camera 800 may have forexample, dimensions and/or parameters shown in Table 1. Thisconfiguration of camera 800 enables for example EFL_(M)=3*EFL_(W) andEFL_(T)=9*EFL_(W) while maintaining a camera height of less than 7 mm.

FIG. 9 a illustrates the user experience of resolution gain vs ZF in anideal optical zoom case. FIG. 9 b illustrates the actual user experienceof resolution gain vs ZF in a common case of two 13 Mega (13M) pixelsub-cameras (one Wide and one Tele) and a 2 Mega (2M) pixel viewer (e.g.display).

For example, assume the Wide and Tele sub-cameras have EFL_(s)fulfilling EFL_(T)=5*EFL_(W). In this case, the starting resolution(ZF=1) will be the 2M of the viewer. As ZF increases by sub-cameradigital zoom, the viewer 2M pixels will sample a smaller “new” FOV(contributing to higher resolution). This new FOV is a function of ZFi.e. FOV_(ZF)=FOV_(W)/ZF. The new FOV_(ZF) is sampled by a smallernumber of pixels (PXC) in the Wide sub-camera (contributing to lowerresolution) according to PXC=13M/(ZF)². As long as PXC>2M (orZF<(13/2)^(0.5)=DZC), the perceived resolution will increase with ZF.For ZF close to 1, the resolution increase will be similar to theresolution increase of an optical zoom. For a digital ZF close to DZC,the resolution increase will be much lower. For a digital ZF>DZC, theresolution will remain constant. A formula describing the resolutiongain (RG) achieved by digital zoom of the Wide sub-camera as a functionof ZF can be written as

RG=RG(W)*(1+CQ*(ZFC−1)*sqrt(tan h(((ZF−1)/CQ*(ZFC−1))²)))

where CQ (typically between 0.7-0.8) represents the camera quality atmaximum resolution and RG(W) is the perceived object resolution of aWide sub-camera image without any digital zoom.

In FIG. 9 b, RG follows this formula for 1<ZF<5. At ZF=5 (defined as“transition ZF” or ZF_(t)), the output switches to the T sub-camera witha corresponding RG(T)=5, where RG(T) is the perceived object resolutionof a T sub-camera image without any digital zoom. In a similar way, thecontinued resolution gain with ZF after the sub-camera switch follows:

RG=RG(T)*(1+CQ*(DZC−1)*sqrt(tan h(((ZF/ZF_(T)−1)/CQ*(DZC−1))²)))

As can be seen from FIG. 9 b, the user experience of resolution gainwith ZF is very different than in an ideal optical zoom case.

FIG. 9 c illustrates a user experience of resolution gain vs. ZF in acommon case of 13M sub cameras and 2M viewer with a three-aperturecamera that includes a Wide sub-camera with EFL_(W), an intermediate Midsub-camera with EFL_(M)=2.35*EFL_(W) and a Tele sub-camera withEFL_(T)=5*EFL_(W). In this case there are two sub-camera transitionsZF_(t1)=2.35 and ZF_(t2)=5. Correspondingly, there are three resolutiongains RG(W)=1, RG(M)=2.35 and RG(T)=5. The figure illustrates thefollowing RG behavior:

From ZF=1 up to ZF=2.35, RG=RG(W)*(1+CQ*(DZC−1)*sqrt(tanh(((ZF/1−1)/CQ*(DZC−1))²)));

From ZF=2.35 up to ZF=5, RG=RG(M)*(1+CQ*(DZC−1)*sqrt(tanh(((ZF/ZF_(T1)−1)/CQ*(DZC−1))²)));

From ZF=5 onwards, RG=RG(T)*(1+CQ*(DZC−1)*sqrt(tanh(((ZF/ZF_(T2)−1)/CQ*(DZC−1))²))).

As can be seen, in this case the user experience of resolution gain vs.ZF is very close to the user experience in an ideal optical zoom.

Thus, according to an example of the presently disclosed subject matter,given an EFL_(W) and an EFL_(T), a Mid sub-camera with respectiveEFL_(M) can be selected based on the geometric mean of the EFL_(W) valueand an EFL_(T) value. According to this example, EFL_(M) is selectedbased on the equation =>√{square root over (EFL_(T)×EFL_(W))}, where insome cases EFL_(M) equals √{square root over (EFL_(T)×EFL_(W))}.

As mentioned above, it is desirable to design a camera having dimensionswhich are as small as possible in order to be suitable to operate withcommonly used image sensors and to fit the thickness of an electronicdevice (e.g. a Smartphone), in which the camera is installed (preferablywithout protruding from the device's casing). Accordingly, in amultiple-aperture (e.g. dual-aperture) camera as disclosed herein it isdesirable to maintain the height of a folded Tele sub-camera as low aspossible. Unlike common cameras (e.g. upright sub-cameras), in a foldedTele sub-camera as disclosed herein the height of the camera is relatedto the dimension of the module in the y axis as shown for example inFIG. 2 and is largely dependent on the diameter of the largest lensamong the lenses in the respective lens module.

At the same time, it is also desirable to achieve good image resolutionwhile providing high zooming effect (e.g. ZF=×5 or greater) andtherefore the aperture diameter in the folded Tele sub-camera must bemaintained sufficiently large to enable to achieve a sufficiently smallF# (e.g. F#=3 or smaller). Notably, the larger the EFL of the Telesub-camera, the larger the aperture must be to maintain a given F#.

Furthermore, in many conventional lens modules (e.g. upright Wide orTele lens modules) with a sensor being larger than the aperture, thediameter of the lenses is designed to be increasingly wider towards thesensor so it is adapted to the field angle of light entering the cameraaperture, which is intended to fall on the entire area of the sensor. Ina folded lens unit, this conventional design of increasing lens diameterwould result in a greater camera height and is therefore undesirable.

Thus, a new folded Tele sub-camera is disclosed herein having a lensmodule with a group of lens elements designed with reduced height whilemaintaining light blockage below a certain value and allowing projectionof incoming light on the entire area of the image sensor.

According to examples of the presently disclosed subject matter, thelens elements in the lens module are not designed with an increasinglylarger diameter towards the sensor. Rather, the diameter of each lenselement in the lens module of the folded Tele sub-camera is reduced insize. The diameter of each lens is determined to be as small as possiblewhile maintaining sufficient light passage through the lens towards thesensor for obtaining desired camera properties (e.g. resolution and SNR)and enabling to continue and provide an image on the entire area (i.e.active pixel area of the sensor) of the image sensor. The image sensorscan be for example, a ⅓″ image sensor and a ¼″ image sensor.

According to certain examples, the diameter of the largest lens elementin the Tele lens module (comprising at least 3 lens elements)substantially does not the diameter of the aperture (218) for allowinglight to enter the Tele sub-camera (i.e. Tele sub-camera aperture).Thus, the diameter of the Tele sub-camera aperture can assist to definemaximal diameter of the lens elements in the Tele lens module.

According to one example, the diameter of the largest lens element inthe Tele lens module is lower than or equal to the diameter of theTele-sub camera aperture. According to another example, the diameter ofthe largest lens element in the Tele lens module does not exceed thediameter of the Tele sub-camera aperture by more than 10%. According toanother example, the diameter of the largest lens element in the Telelens module does not exceed the diameter of the Tele sub-camera apertureby more than 5%. According to yet another example, the diameter of thelargest lens element in the Tele lens module does not exceed thediameter of the Tele sub-camera aperture by more than 2.5%. Examples offolded Tele sub-camera design parameters according to these principlesare described below with reference to FIGS. 10 and 11 and Tables 2-7.

FIGS. 10A-10C show various exemplary Tele lens modules (numbered 220 a,220 b or 220 c) that can be used in a zoom dual-aperture cameradisclosed herein, including as a folded Tele lens. Each module includesa respective group of lens elements. Also shown in FIG. 10A are aperturestop 218, symmetry axis 222 a in a “z” direction, Tele sensor 224 and anadditional cover plate 223.

Lens modules 220 a, 220 b or 220 c include, respectively, 5, 4 and 3lens elements (or simply “elements”). The lens elements are marked L1,L2, L3, L4 and L5 (in lens module 220 a), L1, L2, L3 and L4 (in lensmodule 220 b) and L1, L2 and L3 (in lens module 220c). Notably, theexamples described herein include at least 3 lens elements which canprovide sufficient imaging quality.

Detailed optical data and aspheric surface data is given in Tables 2 and3 for lens module 220 a, in Tables 4 and 5 for lens module 220 b, and inTables 6 and 7 for lens module 220 c. The units of the radius ofcurvature (R), the lens element thickness and/or distances betweenelements along the symmetry axis, and the diameter are expressed in mm.“N_(d)” is the refraction index. “V_(d)” is a parameter indicating lensmaterial color disparity. A large V_(d) indicates a small colordisparity and vice-versa. “BKZ” is a known glass with a known N_(d) andV_(d). The equation of the aspheric surface profiles is expressed by:

$z = {\frac{{cr}^{2}}{1 + \sqrt{1 - {( {1 + k} )c^{2}r^{2}}}} + {\alpha_{1}r^{2}} + {\alpha_{2}r^{4}} + {\alpha_{3}r^{6}} + {\alpha_{4}r^{8}} + {\alpha_{5}r^{10}} + {\alpha_{6}r^{12}} + {\alpha_{7}r^{14}} + {\alpha_{8}{r^{16}.}}}$

where “r” is distance from (and perpendicular to) the symmetry axis, kis the conic coefficient, c=1/R where R is the radius of curvature, anda are coefficients given in Tables 3, 5 and 7. Note that the maximumvalue of r, “max r” =Diameter/2. Also note that in Table 2 (and inTables 4 and 6 below), the distances between various elements (and/orsurfaces) are measured on the symmetry axis Z, wherein the stop is atZ=0. Each number is measured from the previous surface.

TABLE 2 Conic coefficient # Radius (R) Distance N_(d)/V_(d) Diameter k 1Infinite −0.324 4.0 0 2 4.938499 0.779 1.544921/55.9149 4.0 2.2402 353.73119 0.074 4.0 28 4 4.310708 1.217 1.635517/23.9718 4.0 1.2159 52.127431 0.509 3.5 −0.9831 6 7.374006 0.678 1.544921/55.9149 3.6 10.88517 −147.731 0.604 3.5 −12.2 8 −2.28889 0.742 1.635517/23.9718 3.5 −7.66869 −2.97793 0.082 3.9 −5.7863 10 2.411553 0.6 1.544921/55.9149 4.1−6.0953 11 3.111521 6.982 4.0 −8.4191 12 Infinite 0.21 BK7 6.0 0 13Infinite 0.187 6.0 0 14 Infinite 0 6.1 0

TABLE 3 # α₁ α₂ α₃ α₄ α₅ α₆ α₇ α₈ 2 0 −2.5699E−03 −6.5546E−04−2.4933E−05 −1.9717E−05 9.1450E−07 1.8986E−08 0.0000E+00 3 0 4.7508E−04−4.3516E−04 −6.5166E−05 −4.2148E−07 1.0572E−06 4.4021E−08 0.0000E+00 4 0−9.1395E−03 2.5655E−04 −4.5210E−05 7.4472E−06 −1.1011E−06 2.8410E−070.0000E+00 5 0 −1.0827E−02 1.0372E−03 5.0554E−05 −9.5710E−06 1.1448E−05−2.2474E−06 0.0000E+00 6 0 −9.5074E−03 1.0268E−03 2.4209E−04 1.1234E−043.9355E−06 −9.7194E−06 7.9430E−07 7 0 −3.6269E−03 8.7662E−04 7.0010E−046.5578E−05 −2.0053E−05 −4.1923E−06 0.0000E+00 8 0 −1.2355E−02 1.8611E−031.5007E−04 −9.4899E−05 −8.0223E−06 −3.1794E−06 0.0000E+00 9 0−7.3112E−03 9.3354E−04 2.5951E−06 −4.0614E−06 −8.8752E−06 −1.6836E−066.2706E−07 10 0 −2.7777E−03 7.1318E−04 3.0673E−05 −2.3126E−06−2.9513E−06 5.1524E−07 0.0000E+00 11 0 −3.8232E−03 4.8687E−04 4.8505E−052.2064E−06 −4.0755E−06 5.8813E−07 0.0000E+00

TABLE 4 Conic coefficient # Radius Distance N_(d)/V_(d) Diameter k 1Infinite −0.420 4.0 2 4.114235 1.674 1.544921/55.9149 4.0 −0.6679 3−14.5561 0.073 4.0 15.3789 4 76.19695 1.314 1.635517/23.9718 3.9−10.0000 5 3.726602 1.130 3.6 −0.3699 6 5.336503 1.407 1.635517/23.97183.8 −9.4625 7 9.356809 0.839 3.6 −12.2000 8 2.76767 0.5121.544921/55.9149 3.8 −3.0862 9 2.342 3.457 4.0 −2.3717 10 Infinite 0.210BK7 8.0 11 Infinite 0.894 8.0 12 Infinite 0.000 8.0

TABLE 5 # α₁ α₂ α₃ α₄ α₅ α₆ α₇ 2 0 3.1365E−04 −2.4756E−04 −3.2950E−05−3.1474E−06 −6.6837E−07 −9.3198E−08 3 0 1.1887E−03 −5.1479E−04−7.0886E−06 −6.6567E−06 7.3082E−07 −2.1508E−07 4 0 −6.7467E−031.6492E−03 −1.7937E−04 2.4668E−05 −6.1495E−08 −5.8827E−07 5 0−1.8460E−02 3.8467E−03 −5.0388E−04 9.0675E−05 6.3951E−06 −4.2041E−06 6 0−1.0557E−03 5.4851E−04 −1.1124E−04 1.2112E−04 −1.4549E−05 −1.0474E−06 70 −1.3355E−02 7.1465E−03 −1.8536E−03 4.1411E−04 −8.4044E−06 −6.4049E−068 0 −5.9360E−02 6.4070E−03 4.1503E−04 −2.5533E−04 4.3694E−05 −5.0293E−069 0 −5.6451E−02 9.0603E−03 −5.9225E−04 −1.1000E−04 2.2464E−05−1.5043E−06

TABLE 6 Conic coefficient # Radius Distance N_(d)/V_(d) Diameter k 1Infinite 0.060 5.0 0.00 2 7.942 1.682 1.534809/55.6639 5.0 −7.2579 3−15.778 2.040 5.0 17.1752 4 −2.644 2.143 1.639078/23.2529 5.0 −5.3812 5−7.001 0.063 5.0 −8.3079 6 2.300 1.193 1.534809/55.6639 5.0 −0.5654 73.373 7.787 5.0 −0.1016 8 Infinite 0.210 BK7 8.0 9 Infinite 0.200 8.0

TABLE 7 # α₁ α₂ α₃ α₄ α₅ α₆ α₇ 2 0 −3.4545E−04 −2.6977E−04 −6.3091E−06−7.6965E−07 0.0000E+00 0.0000E+00 3 0 −1.2414E−03 −3.0118E−04 1.6812E−05−1.6865E−06 1.9446E−07 −1.1391E−08 4 0 3.0073E−03 −4.8811E−04 9.4948E−05−5.7587E−06 1.0543E−07 0.0000E+00 5 0 3.6847E−03 −4.8608E−04 7.2121E−05−2.9304E−06 0.0000E+00 0.0000E+00 6 0 −1.5774E−02 1.4580E−03 −2.6302E−042.3905E−05 −1.1017E−06 0.0000E+00 7 0 −8.6658E−03 1.2548E−03 −3.6145E−045.0797E−05 −3.8486E−06 1.1039E−07

The following terms are defined: “Lens optical height” “H” is themaximal diameter of the optically used area of each lens element, i.e.the area through which light passes directly from the camera aperture tothe sensor to form an image. The term is illustrated in FIG. 11A for afour-element lens module. Each element has a respective optical height“H_(a)”. The figure shows H/2 as the distance between the symmetry axisand the tip of marked arrows. The “camera optical height” is the largestoptical height out of all lens elements, in this case H₁.

A “blocked light percentage” (per viewing angle) is defined as thepercentage of light arriving at the camera from a very far object at acertain viewing angle (horizontal and vertical) and which enters thecamera aperture but does not reach the image sensor. Notably, therelative light blockage increases with a decrease in the diameter of thelens elements. FIG. 11B illustrates a blockage 240 of part of the lightcaused by a light stop 250 inserted (by way of example) between elementsL3 and L4 of a four-element Tele lens. Light stop, also known simply as“stop”, is configured to prevent light from reaching the lens edge andbeing scattered in all directions.

According to the presently disclosed subject matter, the diameter of thelens elements in the Tele lens module are determined such that lightwhich is blocked by light stops does not prevent more than a predefinedpercentage of the incoming light from reaching the image sensor.

The Tele lenses disclosed above allow the use of a large Tele sensor(>4.5 mm×3.35 mm) enabling high pixel count (e.g. 13 Mega pixels). Theyprovide a low camera optical height that enables a low camera moduleheight (e.g. <1.25*(1+EFL/F#)=1.25*(1+camera aperture)), see also FIGS.12 and 13.

The folded Tele lenses disclosed herein allow a long EFL (e.g. >10 mm)for high zoom, a low F# (e.g. <3) to obtain more light and opticalresolution, and a low percentage of blocked light (<25%) for all viewingangles. As shown above, a folded Tele lens module may include, forexample, 3-5 lens elements. This combination of lens elements enables toobtain a high image quality at a low price.

It is noted that the lens elements of the Tele lens module are held inplace by a special structure (e.g. barrel), for example by a plastic tub(cold barrel). Thus, the Tele lens module discussed herein is consideredto include the structure holding the lens elements in place (barrel) aswell as a substrate (e.g. one or more PCBs). The one or two magnets canbe positioned on the substrate as illustrated in FIGS. 12 and 13 or onthe sides of the substrates. In any case their height substantially doesnot exceed the height of the Tele lens module.

FIG. 12 shows in (a) an isometric view and in (b) an external view of acamera disclosed herein and numbered 1200. Camera 1200 includes atwo-magnet (1202 and 1204), two-coil (1206 and 1208) AF mechanism forthe folded Tele lens. Each pair of magnet-coils is disposed so as toprovide a force that moves a Tele lens 1210 along its symmetry axis. Theforce (and movement) are countered (and reversed) by a spring 1212.

FIG. 13 shows in (a) an isometric view and in (b) an external view of acamera disclosed herein and numbered 1300. In contrast with camera 1200,camera 1300 includes a one-magnet (1302), one-coil (1306) and spring(1312) AF mechanism for the folded Tele lens. AF mechanisms illustratedin FIG. 12 and FIG. 13 are configured to operate according to theprinciples of voice coil actuator (VCA, commonly known as “magneticactuators”).

This AF mechanism is specifically designed to maintain a low cameraprofile. According to one example, the AF mechanism is designed to fitlaterally on one or two faces of the Tele lens module, while the otherfaces remain clear of the AF mechanism parts.

Specifically, one or two magnets (coupled magnetically to respectivecoils) are designed with a height substantially not exceeding the heightof the Tele lens module in order to avoid any significant contributionto the overall height of the Folded Tele sub-camera.

This design is illustrated in FIG. 12 (showing an AF design with twomagnets) and FIG. 13 (showing an AF design with one magnet). Note thatwhile the magnets are positioned upright on one or two sides of the Telelens module, the two other plains (on the object side, marked by arrowOS, and substrate side, marked by arrow SS), located perpendicular tothe magnets, remain clear of the magnets. This design of the AFmechanism in general and the magnets, specifically significantly reduces(or, in some configurations, completely avoids) an increase in theoverall height of the Tele sub-camera which may have been otherwiseinduced by the AF mechanism.

According to one example, the height of the magnets is lower than orequal to the height of the Tele lens module (defined for example by thehighest lens). According to another example, the height of the magnetsdoes not exceed the height of the Tele lens module by more than 10%.According to another example, the height of the magnets does not exceedthe height of the Tele lens module by more than 5%. According to anotherexample, the height of the magnets does not exceed the height of theTele lens module by more than 2.5%.

The entire camera (including the AF mechanism) may be packaged in a lowprofile mechanical packaging (casing) 1250 with height H_(T) (heighttotal), see FIG. 12( b), enabling inclusion of a zoom dual or tripleaperture camera disclosed herein in a low profile cell-phone, such thatH_(T) is equal to or smaller than 6.5 mm and in some examples equal toor smaller than 5.7.

FIG. 14 shows a schematic illustration of an example of a portableelectronic device with an integrated dual-aperture camera with foldedTele lens module, according to an example of the presently disclosedsubject matter. As illustrated in the image, the camera 1450 (includingdual aperture camera with folded Tele lens module and the camera casing)is fully integrated in the portable electronic device 1400 and does notprotrude from the device casing. The camera is oriented within theportable device such that its longitudinal dimension is positionedhorizontally with respect to the device. Due to the folded optical pathof the Tele sub-camera it can provide a high zooming effect (e.g. ×5 orgreater) while having a structure not protruding from the casing of theelectronic device (e.g. Smartphone).

While this disclosure has been described in terms of certain embodimentsand generally associated methods, alterations and permutations of theembodiments and methods will be apparent to those skilled in the art.The disclosure is to be understood as not limited by the specificembodiments described herein, but only by the scope of the appendedclaims.

1. A digital camera comprising: a Wide sub-camera and a Tele sub-camera;the Wide sub-camera comprises a Wide lens module and a Wide imagesensor, the Wide lens module having a Wide lens symmetry axis along afirst optical path between an object side and the Wide image sensor; theWide sub-camera configured to provide a Wide image; the Tele sub-cameracomprises a Tele lens module and a Tele image sensor and a firstreflecting element; the Tele lens module having a Tele lens symmetryaxis along a second optical path, the Tele lens symmetry axis positionedsubstantially perpendicular to the Wide lens symmetry axis, the Telesub-camera configured to provide a Tele image; the first reflectingelement having a first reflecting element symmetry axis inclinedsubstantially at 45 degrees to both the Wide lens symmetry axis and theTele lens symmetry axis and operative to provide a folded optical pathbetween the object and the Tele image sensor; wherein the Tele lensmodule comprises a group of at least 3 lens elements and wherein thelens elements in the group are designed to have a diameter substantiallynot exceeding the diameter of an aperture of the Tele sub-camera.
 2. Thecamera of claim 1 wherein lens elements in the group are designed suchthat blocked light does not exceed 25 percent of light entering the Telelens module.
 3. The camera of claim 1 wherein the Tele lens module isconfigured to enable to generate an image on an entire area of the Teleimage sensor.
 4. The camera of claim 1 wherein the Tele sub-camera isconfigured with an effective focal length (EFL)>9 mm, an F#<3 and toblock not more than 25% of light entering the Tele sub-camera aperturefor all viewing angles.
 5. The camera of claim 1 wherein the Tele lensmodule is characterized by a height not exceeding 5.7 mm.
 6. The cameraof claim 1 wherein the Tele image sensor lies in a plane substantiallyperpendicular to the Tele lens symmetry axis.
 7. The camera of claim 1further comprising a Tele auto-focus (AF) mechanism configured to movethe Tele lens along the Tele symmetry axis; the AF mechanism having aheight substantially not exceeding the height of a Tele lens module. 8.The camera of claim 7 wherein the AF mechanism comprises one or moremagnets coupled to respective coils, positioned laterally on one or twosides of the Tele lens module, the magnets having a height substantiallynot exceeding the height of the Tele lens module.
 9. The camera of claim8 wherein the AF mechanism comprises only one magnet coupled to arespective coil.
 10. The camera of claim 1 further comprising a secondreflecting element positioned in the second optical path between theTele lens module and the Tele image sensor, the second reflectingelement being configured to direct light that propagates parallel to thesecond optical path to the first optical path, wherein the Tele imagesensor lies in a plane substantially perpendicular to the Wide lenssymmetry axis.
 11. The camera of claim 10 further comprising a Teleauto-focus (AF) mechanism configured to move the second reflectingelement along a second reflecting element symmetry axis.
 12. The cameraof claim 11 further comprising a Tele AF mechanism configured to movethe Tele lens module along the Tele lens symmetry axis.
 13. The cameraof claim 1 wherein the Wide lens module has a Wide field of view FOV_(W)and the Tele lens module has a Tele field of view FOV_(T) narrower thanFOV_(W); the camera further comprises a Mid sub-camera that includes aMid lens module with a field of view FOV_(M) that fulfillsFOV_(W)>FOV_(M)>FOV_(T) and a Mid image sensor, the Mid lens having aMid lens symmetry axis; the Mid camera is configured to provide a Midimage; wherein the camera is operatively connected to at least oneprocessor configured to process the Tele image and the Wide image intoan output image; wherein the at least one processor is furtherconfigured to process the Mid image together with the Tele image or theWide image into an output image.
 14. The camera of claim 13 wherein theMid sub-camera is configured with an EFL which equals to a geometricaverage of an EFL of the Wide sub-camera and an EFL of the Telesub-camera.
 15. The camera of claim 13 wherein the Mid lens symmetryaxis is substantially perpendicular to the Wide lens symmetry axis andthe Mid image sensor lies in a plane substantially perpendicular to theMid lens symmetry axis; and wherein the Tele image sensor lies in aplane substantially perpendicular to the Tele lens symmetry axis. 16.The camera of claim 13 further comprising a Mid auto-focus (AF)mechanism configured to move the Mid lens module along the Mid symmetryaxis, which is substantially perpendicular to the Wide lens symmetryaxis; and a Tele AF mechanism configured to move the Tele lens modulealong the Tele symmetry axis; the Mid AF mechanism and Tele AF mechanismhaving a height substantially not exceeding the height of the Tele lensmodule.
 17. The camera of claim 15 further comprising a third reflectingelement inclined substantially at 45 degrees to both the Wide lenssymmetry axis and the Mid lens symmetry axis; the third reflectingelement is configured to provide a folded optical path between theobject side and the Mid image sensor.
 18. The camera of claim 13 furthercomprising a fourth reflecting element positioned in a fourth opticalpath between the Mid lens and the Mid image sensor, the fourthreflecting element configured to direct light that propagates parallelto the second optical path to the first optical path, wherein the Midimage sensor lies in a plane substantially parallel to the Mid lenssymmetry axis.
 19. The camera of claim 13, operatively connected to atleast one processor configured to output an output image formed by usingWide and Mid images for a ZF that sets a FOV between FOV_(W) andFOV_(M).
 20. The camera of claim 13, operatively connected to at leastone processor configured to output an output image formed by using Midand Tele images for a ZF that sets a FOV between FOV_(M) and FOV_(T).21. The camera of claim 16 wherein the Mid AF mechanism comprises one ormore magnets coupled to respective coils, positioned laterally on one ortwo sides of the Tele lens module, the magnets having a heightsubstantially not exceeding the height of the Tele lens module.
 22. Thecamera of claim 21 wherein the Mid AF mechanism comprises only onemagnet coupled to a respective coil.
 23. A mobile electronic devicecomprising an internal camera integrated inside a housing of theelectronic device, the camera comprising: a Wide sub-camera and a Telesub-camera; the Wide sub-camera comprising a Wide lens module and a Wideimage sensor, the Wide lens module having a Wide lens symmetry axisalong a first optical path between an object side and the Wide imagesensor; the Wide sub-camera configured to provide a Wide image; a Telesub-camera comprising a Tele lens module and a Tele image sensor and afirst reflecting element; the Tele lens module having a Tele lenssymmetry axis along a second optical path, the Tele lens symmetry axispositioned substantially perpendicular to the Wide lens symmetry axis;the Tele camera configured to provide a Tele image; the first reflectingelement having a first reflecting element symmetry axis inclinedsubstantially at 45 degrees to both the Wide lens symmetry axis and theTele lens symmetry axis and operative to provide a folded optical pathbetween the object and the Tele image sensor; and wherein the Tele lensmodule comprises a group of 3 to 5 lens elements and wherein the lenselements in the group are designed to have a diameter not substantiallyexceeding the diameter of an aperture of the Tele sub-camera.
 24. Theelectronic mobile device of claim 23 wherein the lens elements in thegroup are designed such that blocked light does not exceed 25% of lightentering the Tele lens module.
 25. The electronic mobile device of claim23 wherein the group is designed to enable to generate an image on anentire area of the Tele image sensor.
 26. The electronic mobile deviceof claim 23 wherein the Tele sub-camera is configured with an EFL>9 mm,an F#<3 and to block not more than 25% of light entering the Telesub-camera aperture for all viewing angles.
 27. The electronic mobiledevice of claim 23 wherein the Tele lens module is characterized by aheight not exceeding 6.5 mm.
 28. The electronic mobile device of claim23 wherein the Tele sub-camera further comprises a Tele auto-focus (AF)mechanism configured to move the Tele lens along the Tele symmetry axis;the AF mechanism comprises one or more magnets coupled to respectivecoils, positioned laterally on one or two sides of the Tele lens module,the magnets having a height substantially not exceeding the height ofthe Tele lens module.
 29. A digital camera configured to be integratedwithin a casing of an electronic device, the camera comprising: a Widesub-camera, a Tele sub-camera and a Tele auto-focus (AF) mechanism; theWide sub-camera comprising a Wide lens module and a Wide image sensor,the Wide lens module having a Wide lens symmetry axis along a firstoptical path between an object side and the Wide image sensor; the Widesub-camera configured to provide a Wide image; a Tele sub-cameracomprising a Tele lens module and a Tele image sensor and a firstreflecting element; the Tele lens module having a Tele lens symmetryaxis along a second optical path, the Tele lens symmetry axis positionedsubstantially perpendicular to the Wide lens symmetry axis; the Telecamera configured to provide a Tele image; the first reflecting elementhaving a first reflecting element symmetry axis inclined substantiallyat 45 degrees to both the Wide lens symmetry axis and the Tele lenssymmetry axis and operative to provide a folded optical path between theobject and the Tele image sensor; wherein the Tele lens module comprisesa group of 3 to 5 lens elements and wherein the lens elements in thegroup are designed to have a diameter not substantially exceeding thediameter of an aperture of the Tele sub-camera, to enable the generationof an image on an entire area of the Tele image sensor, and to enablepassage of at least 75% of light entering the Tele lens module, towardsthe Tele image sensor; wherein the Tele AF mechanism is configured tomove the Tele lens along the Tele symmetry axis; the AF mechanismcomprises one or more magnets coupled to respective coils, positionedlaterally on one or two sides of to the Tele lens module, the magnetshaving a height substantially not exceeding the height of the Tele lensmodule.
 30. The camera of claim 29 wherein the Tele sub-camera isconfigured with an EFL>9 mm and an F#<3 and wherein the Tele lens moduleis characterized by a height not exceeding 6.5 mm.